Lynk Pharmaceuticals Announces Positive Phase III Topline Data of Zemprocitinib (LNK01001) in Rheumatoid Arthritis
HANGZHOU, China, SHANGHAI and BOSTON, Jan. 12, 2026 /PRNewswire/ -- Lynk Pharmaceuticals Co., Ltd. (hereinafter referred to as "Lynk Pharmaceuticals"), a clinical stage innovative drug development company focused on developing innovative therapies for immune and inflammatory diseases, today announced positive topline results from its Phase III clinical trial evaluating zemprocitinib (LNK01001) in patients with moderate to severe active rheumatoid arthritis (RA). The study met its primary and key secondary efficacy endpoints, demonstrating statistically significant improvements versus placebo (P < 0.0001), with a favorable safety and tolerability profile.
This randomized, double-blind, placebo-controlled Phase III study (CTR20232969, NCT06276998) evaluated the efficacy and safety of zemprocitinib in patients with moderate to severe active RA who had an inadequate response to biologic disease-modifying antirheumatic drugs (bDMARDs). The trial was led by Professor Xiaofeng Zeng from Peking Union Medical College Hospital and Chinese Academy of Medical Sciences, and enrolled a total of 430 patients, who were randomized 1:1 to receive zemprocitinib 12 mg twice daily or placebo (PBO) twice daily. The primary endpoint was the proportion of patients achieving an ACR20 response at Week 24, with key secondary endpoints including the proportion of patients achieving ACR50 and DAS28 (CRP) ≤ 3.2 at Week 24.
The study results showed that response rates in the zemprocitinib treatment group were significantly higher than those in the placebo group across all primary and key secondary efficacy endpoints, with the differences reaching statistical significance. Specifically, the ACR20 response rates at Week 12 and Week 24 vs. PBO were 74.0% versus 29.9% (P < 0.0001) and 79.1% versus 39.7% (P < 0.0001), respectively. The ACR50 response rates at Week 12 and Week 24 vs. PBO were 41.4% versus 9.3% (P < 0.0001) and 55.8% versus 22.0% (P < 0.0001), respectively. The proportion of patients achieving DAS28 (CRP) ≤ 3.2 at Week 12 and Week 24 vs. PBO were 51.2% versus 15.0% (P < 0.0001) and 67.0% versus 23.4% (P < 0.0001), respectively. In terms of safety, zemprocitinib was generally well tolerated. The majority of treatment emergent adverse events (TEAEs) were mild to moderate in severity (Grade 1–2). The incidence of serious adverse events was comparable between the zemprocitinib and placebo groups, and no new safety signals were observed. The overall safety profile was consistent with previous studies. The primary results of this study are planned to be formally presented at an upcoming international scientific conference.
Professor Xiaofeng Zeng, the principal investigator of this study from Peking Union Medical College Hospital and Chinese Academy of Medical Sciences, said: "Rheumatoid arthritis is a chronic, progressive autoimmune disease that can severely impact patients' quality of life and physical health. In this Phase III study, zemprocitinib demonstrated strong efficacy, showing statistically significant improvements across the primary and key secondary efficacy endpoints, while maintaining a favorable safety and tolerability profile. These results suggest that zemprocitinib has the potential to offer a new treatment option for this patient population."
Dr. Zhao-Kui (ZK) Wan, Founder and Chief Executive Officer of Lynk Pharmaceuticals, said: "We are very encouraged by the positive topline results from this Phase III trial of zemprocitinib. This represents the first disclosed trial results in China for a selective JAK1 inhibitor in patients with moderate to severe rheumatoid arthritis who have had an inadequate response or intolerance to prior biologic therapies. We believe that zemprocitinib, as a promising oral therapy, has the potential to offer a meaningful new treatment option for patients with rheumatoid arthritis. We would also like to express our sincere gratitude to the patients, investigators, and all teams involved for their dedication and contributions in achieving this important milestone."
Gaobo Zhou, Chief Investment Officer of Simcere, said: "As the commercialization partner of zemprocitinib, we are pleased to see the strong performance of this Phase III study in rheumatoid arthritis. These results further highlight the therapeutic potential of zemprocitinib. We will continue to support its subsequent development and remain committed to bringing improved oral treatment options to patients with rheumatoid arthritis."
About Zemprocitinib (LNK01001):
Zemprocitinib (LNK01001) is a highly selective, next generation JAK1 inhibitor with best in class potential, being developed for the treatment of rheumatoid arthritis, ankylosing spondylitis, atopic dermatitis, and vitiligo. Compared with first-generation JAK inhibitors with lower selectivity, zemprocitinib exhibits significantly greater selectivity for JAK1, which may enhance efficacy while reducing off-target adverse effects. Zemprocitinib potently and dose-dependently inhibits multiple inflammation-related signaling pathways mediated by JAK1. In March 2022, Lynk Pharmaceuticals entered into a commercialization collaboration with Simcere to jointly advance the development and commercialization of zemprocitinib for rheumatoid arthritis and ankylosing spondylitis in Greater China.
About Lynk Pharmaceuticals:
Lynk Pharmaceuticals, a clinical stage company, was founded by senior drug R&D experts and executives from Pfizer, Merck, and Johnson & Johnson. Lynk Pharmaceuticals is dedicated to the discovery and development of innovative drugs for the treatment of immune and inflammatory diseases. Driven by a higher goal, Lynk Pharmaceuticals aims to be a market leader to address unmet medical demands by the development of innovative therapies. We thrive to provide differentiated innovative therapies to benefit patients globally. To date, Lynk Pharmaceuticals has independently developed several innovative new drug candidates and successfully completed a number of clinical studies.
About Simcere:
Simcere Pharmaceutical Group Limited (2096.HK) is a pharmaceutical company driven by innovation and focusing on four therapeutic areas including Neuroscience, Oncology, Autoimmune Diseases and Anti-infection. We proactively explore areas with significant unmet needs, and our mission is For patients, for life. Driven by our in-house R&D efforts and synergistic innovation, Simcere has established strategic cooperation partnerships with many innovative companies and research institutes.
SOURCE Lynk Pharmaceuticals Co., Ltd.
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